Delimitation of application of stationary and non-stationary models of the gas pipeline operation

Abstract

The author of work offers way of delimitation of preferable application of a stationary model, and model which describes non-stationary process of gas pipeline operation. Scientifically reasonable choice of a settlement model is key question for gas pipelines calculation. The importance of such differentiation in practice is that it makes sense to use simpler stationary model if variability of parameters is not big and doesn't entail inadmissible errors. The author of work shows this way on concrete models: standard calculation of a stationary operating mode of gas pipeline, offered, for example, in norms of design and calculation of well-known system of equations which describes non-stationary process by the way with variable coefficients. This way of calculation was significantly modified by author for accounting of heat exchange, and also, for gravity influence. The specified adjustment is described in detail in other publication of author. In offered way of differentiation of scopes of stationary and non-stationary models of gas pipeline hydraulic calculation, comparison of results of calculation of both models according to same regime data is used. Results of calculation of both models have to be compared in sizes of calculated losses of energy of gas compression in gas pipeline. The choice, for example, of this parameter is caused by that in solution of specific objective concerning gas transport, size of losses of energy of gas compression in gas pipeline defines main part of expenses of energy carriers at compressor station. Therefore it is key indicator in an assessment of an operating mode of gas transmission system and in choice of most economically expedient option of an operating mode. The essence of definition of required border consists in that distinctions of results of calculation for both methods which are exposed to differentiation, are comparable to errors of these methods. The application of offered way is shown on calculation of concrete example. For all counted parameters, settlement ratios are offered, and results of calculation, for reviewed example, presented by numbers or graphically.